JPS62250788A - Movie signal processor - Google Patents

Abstract

PURPOSE:To attain an excellent reproduction or a transmission signal by providing an integrating means to integrate a phase error, and controlling the clock phase of a clock generating means by using the integral value of the phase errors from the said means to eliminate the distortion in the higher part of a brightness signal or in a color signal. CONSTITUTION:The reference phase signal added at the time of recording is extracted from the output Y-signal of a TBC 11 by a reference phase signal extractor 33, and the phase of a resulting signal is compared with that of the output reference color subcarrier wave of a sync generator 15 by a phase comparator 34, and thus obtained phase error is integrated by an integrator 23, and the clock and the start pulse of a PLL II 35 that generates a read clock 22 and a read start pulse 38 for TBCs 11 and 12 are controlled by the integral value above mentioned. Further, in order to stabilize the phase comparison error from the phase comparator 34 and the integral value from the integrator 23, the operation timings of a phase comparator 39 and a phase shifter 37 are made precede to that of the phase comparator 34. As a result, a signal excellent in quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention can be used in recording and reproducing devices such as VTRs and video signal transmission devices, and is effective in obtaining good high-frequency characteristics of luminance signals and characteristics of color signals. It is.

2. Description of the Related Art Currently, VTRs used for broadcasting are mainly tape widths of 1 inch or 2 inches, and their video signal recording method is to directly frequency modulate the composite video signal. During this recording/reproducing process, time axis fluctuations occur due to uneven rotation of the head, uneven running of the tape, and the like.

This variation is corrected by a time base corrector (TBC) during playback using a horizontal synchronization signal and a burst signal in the playback video signal. However, in this method, the color signal is NT
In the case of the FSO method, it is quadrature two-phase modulated with a 3.58 MHz subcarrier and superimposed on the luminance signal, so
When the frequency is modulated, it is separated from the modulation carrier, so noise reduction, which is a characteristic of FM, is not sufficient, and T
The color subcarrier has a phase fluctuation due to the residual wrinkle of BC, which becomes phase noise, and the degree of convergence of the color vector is not sufficient.

From this point of view, as described in Japanese Patent Application Laid-Open No. 61-41294, a recording method that improves the S/N in the amplitude and phase direction of the color signal and improves the convergence is based on two components of the color signal. There is a method of frequency-modulating the signal and recording it, correcting the time axis during playback, and then modulating (encoding) it with a reference subcarrier and adding it to the luminance signal to create a composite video signal. According to this method, the color signal (component signal) is also recorded as FM in the baseband, so it can be reproduced with good S/N, and since it is encoded with the standard subcarrier, it does not have phase noise and has good quality. It is possible to obtain a reproduced color signal.

A conventional example of this method is shown in FIG. 4 and will be described.

In FIG. 4, 1, 2.3 are the luminance signals (1
), R-! Signal, B-! Signal input terminal, 26 is a synchronization signal generator, 6 is a time axis compressor, 4.6 is a frequency modulator, 7
．． 8 is a head, 9.10 is a frequency demodulator, 11.12 is a TBC, 14 is a reference signal input terminal, 16 is a sync generator, 16 is an encoder, 18.19, 20.21 are respectively, ! .

These are R-Y, B-Y signal, and composite video signal output terminals. Applied to terminal 1! The signal is modulated by a frequency modulator 4 and recorded on a tape by a head 7. On the other hand, terminal 2.3
Two color signal components R-! applied to R-! Signal, B-Y signal becomes RY signal! The synchronization signal generated by the synchronization signal generator 26 is added to the horizontal synchronization signal in the signal by the adder 26, and the time base is compressed line by line by the time base compressor 6. One signal, such as Y-R-Y, B-Y, old, etc. (R-! is R- compressed to A line.
! The signal is then modulated by a frequency modulator 6 and recorded on tape by a head 8. The brightness signal and the color signal form separate tracks by the head 7 and the head 8, and are recorded on the tape. During playback, it was played from head 7! After the signal is demodulated by the frequency demodulator 9, the TB
The time axis is corrected with Cl 1. Further, the color signal reproduced from the head 8 is demodulated by the frequency demodulator 10, and then
The TBC 12 corrects the time axis and expands it to the original time axis. TBCl 1 and 12 write signals to the memory by write signals created from horizontal synchronization signals in the reproduced and demodulated signals, and write signals to the memory at terminal 14.
By reading the signal from the memory using the read clock 22 generated by the sync generator 16 based on the reference signal applied to the sync generator 16, time axis correction and expansion operations are performed. Also, here we remove the synchronization signal,! A reference synchronization signal 24 created by a sync generator 16 is added to the signal by an adder 13. In this way, the noise-free synchronization signal and the terminals 18 and 19 are replaced.
．． At 20, reproduced Y, RY, and B signals are obtained. On the other hand, the output R-Y and B-Y signals of TBCl 2 are encoded by the encoder 16 using the reference subcarrier 27 created by the sync generator 16, and are encoded by the adder 17! signal, and a reproduced composite video signal is obtained at the terminal 21.

In this method, the τ, Ft-Y, and B-Y signals are input, so when recording a composite video signal, the decoder separates them into Y, R-Y, and B-Y signals, and then .3
It will lead you to. During this separation, a comb filter using line correlation is generally used to widen the band of the luminance signal and one color signal.

Problems to be Solved by the Invention When a luminance signal and nine color signals are separated using a comb filter, the color signal is mixed into the luminance signal and the luminance signal is mixed into the color signal in uncorrelated parts. Color signal components RY, B-
! After the signal is recorded and reproduced, it is modulated by the encoder again to become a carrier color signal, and then added to the reproduced luminance signal, but the carrier color signal before being demodulated to R-Y and B-Y during modulation. When modulated with a carrier wave having the same phase as the color signal and added with the same phase as the color signal mixed into the luminance signal, the mixed components are restored to their original state. If this is done, the high-frequency components of the luminance signal will also be transmitted mixed with the chrominance signal, and will be added to the signal transmitted in the luminance signal band again in the correct phase, making it possible to obtain a good signal. Further, the color signal is also restored to its original state, and a good signal without color shift or change in saturation is obtained. However, in general, the phase of the color subcarrier of the output signal of the VTR can be adjusted freely with respect to the phase of the color subcarrier of the reference signal from the input terminal 14 in the TBC in order to adjust the delay with other video signal systems. It is made possible to change. Further, the phase of the color subcarrier of the input composite video signal during recording is equal to four fields in the case of an NTSC signal, but the phase relationship between the reproduced signal and the reference input signal is often determined by odd-even fields. In such a case, the phase of the color subcarrier modulated by the R-Y and B-Y signals and the phase of the original composite video signal are not determined. When modulated with a phase opposite to the original, colors in uncorrelated parts disappear, and the high range of the luminance signal disappears.

Furthermore, if the phases do not match completely, distortion will appear in the high frequency range of the luminance signal and the color signal.

This phenomenon will also occur, albeit to a different extent, even if a low-pass filter or a bandpass filter is used instead of a comb filter to separate the luminance signal and one color signal.

The present invention provides a means for removing such distortions in the high frequency range of the luminance signal and color signals to obtain good reproduction or transmission signals.

Means for Solving the Problems The present invention separates a composite video signal into a luminance signal and two color signal components, records/reproduces or transmits the signals, modulates the two color signal components again, and superimposes them on the luminance signal. A video signal processing device for obtaining a composite video signal, the video signal processing device comprising a luminance signal to be recorded or transmitted, a first signal representing the phase of a color subcarrier in the original composite video signal together with at least one of two color signal components. a transmission means for transmitting a signal; a storage means for storing the luminance signal, two color signals, and a first signal; and a clock generator that supplies a signal read clock to the storage means and allows the phase of the clock to be arbitrarily varied. and first phase comparison means for detecting a phase error between the phase of the first signal read from the storage means and the phase of a color subcarrier modulated by the two reproduced or transmitted color signal components. , an integrating means for integrating the phase error, and the clock phase of the clock generating means is controlled by the integrated value of the phase error from the integrating means.

Furthermore, the present invention separates a composite video signal into a luminance signal and two color signal components, records, reproduces or transmits the signal, modulates the two color signal components again, and superimposes the two color signal components on the luminance signal to obtain a composite video signal. A video signal processing device, the transmission means for transmitting a luminance signal to be recorded or transmitted, a first signal representing the phase of a color subcarrier in the original composite video signal together with at least one of two color signal components. a storage means for storing the luminance signal, two color signals and a first signal; a clock generation means for supplying a signal readout clock to the storage means; and a phase of the first signal read from the storage means. and a second phase comparison means for detecting a phase error between the color subcarrier and the phase of the color subcarrier modulated by the two reproduced or transmitted color signal components; The video signal processing device is characterized in that it is provided with readout control means for controlling the signal readout phase from the means in units of one cycle or a plurality of cycles of the clock.

Furthermore, the present invention separates a composite video signal into a luminance signal and two color signal components, records, reproduces or transmits the signal, modulates the two color signal components again, and superimposes the two color signal components on the luminance signal to obtain a composite video signal. A video signal processing device, the transmission means for transmitting a luminance signal to be recorded or transmitted, a first signal representing the phase of a color subcarrier in the original composite video signal together with at least one of two color signal components. a storage means for storing the luminance signal, two color signals, and a first signal; a clock generation means for supplying a signal readout clock to the storage means and capable of arbitrarily varying the phase of the clock; and the storage means. The first . a second phase comparison means, and an integration means for integrating the phase error of the first phase comparison means;
readout control means that is controlled by the output of the second phase comparison means and controls the signal readout phase from the storage means in units of one cycle or a plurality of cycles of the clock; The video signal processing apparatus is characterized in that the clock phase of the black and black generating means is controlled by the integral value of the phase error from the integrating means, which is operated before the phase comparing means.

Effect By configuring the above means, the signal that is reproduced or transmitted, encoded again, and returned to the composite video signal is either the same as the original input signal in terms of the high frequency range of the luminance signal, the phase of the color signal, or is distorted. Since it is minimized, the resolution is good even in areas where there is no correlation, and a high-quality signal with no or little color shift is obtained.

Embodiment FIG. 1 shows a block diagram of an embodiment of the present invention, and the present invention will be explained. In FIG. 1, the same numbers as in FIG. 4 represent the same things and perform the same operations. 28 is a composite video signal input terminal, 29 is a reference phase signal generator, 36 is a decoder,
3o is an adder, 31 is a video signal phase adjustment signal input terminal,
32 is a color subcarrier phase adjustment signal input terminal, 33 is a reference phase signal extractor, 34 is a phase comparator, 23 is an integrator;
8 is a read start pulse. The composite video signal applied to the terminal 28 is separated into Y, RY, and B-τ signals by a decoder 36. At this time, in the uncorrelated part,! Color signal components are present in the R-Y and B-Y signals! Signal components remain. R-Y.

The recording process of the BY signal is the same as that shown in FIG. on the other hand,!
The signal is generated from the color subcarrier in the input composite video signal (created from a burst signal, VIR signal, etc.) and the reference phase signal generator 2.
9 (a signal with the same frequency as the color subcarrier or a signal synchronized with this, in the following explanation, the reference phase signal created by 9) is the same frequency as the color subcarrier (3.58 M
Hz)) is added to a predetermined position (vertical blanking, burst signal position, etc., in the following explanation, treated as one line within vertical blanking) by the adder 30, and the tape is added in the same manner as in FIG. recorded in During playback, do the same as in Figure 4 and play back to the output of TBCll! The signal is
The reproduced R-D, BY signals are obtained at the output of the TBCl 2, the reproduced Y, RY, BY signals are obtained at the terminals 18, 19, 20, and the reproduced composite video signal is obtained at the terminal 21.

Here, the color subcarrier 27 generated by the sync generator 16 is synchronized with this signal when a signal is applied to the reference signal input terminal 14, and becomes free-running when no signal is applied. In addition, color subcarrier phase adjustment signal input terminal 3
The phase relationship with the input signal at the terminal 14 can be arbitrarily adjusted by the signal from the terminal 14. Therefore, in the example of FIG. 4, the relationship between the phase of the TBC output signal and the phase of the color subcarrier 270 is not determined.
This causes the problems mentioned above. Further, even in a device having a simple configuration in which the phase of the output video signal or the phase of the color subcarrier is not varied, the following inconvenience occurs.

That is, in order to obtain continuity of the synchronization signal during editing, the VTR with the configuration shown in FIGS. is servo-controlled to match the odd and even fields of the signal. However, in the case of an NTSG signal, the relationship between the phase of the color subcarrier and the field is the same for four fields. That is, 1st. Third or second.
In the fourth field, the synchronization signal is the same, but the color subcarrier is inverted. In the above-mentioned servo control, the output color subcarrier 27 of the sync generator 16 and the first, third and second fields of the signal reproduced from the tape are controlled. Although the fourth field can be distinguished, the first and third fields and the second and fourth fields cannot be distinguished. Therefore, 1
Even if the reproduced signal and the color subcarrier are internally matched in phase for a reproduced signal in one state, when the reproduced signal is reproduced in the opposite state, the phases will be reversed, resulting in the worst condition. This problem can be solved by using servo control that can also distinguish between the 1st and 4th fields (known color frame servo), but this has the drawbacks of complicating the circuit and lengthening the lead-in time during editing. . Moreover, even if this is done, terminal 31. terminal 3
It is invalid for devices that perform more than 2 types of control.

From the above points, in the present invention, as shown in the embodiment in FIG. 1, the output of TBCll! From the signal, the reference phase signal added at the time of recording is extracted by the reference phase signal extractor 33, the phase is compared with the output reference color subcarrier 27 of the sync generator 16 by the phase comparator 34, and the obtained phase error is integrated. The phase of the clock and start pulse of the PLL 135 which generates the read clock 22 and read start pulse 38 of TBCll and 12 is controlled by the integrated value.

As a result, the readout phase of the signals from TBCll and 12 is continuously varied, so that the output of the TBC always has the residual color subcarrier in the input video signal that has the same phase as the color subcarrier 27! , RY, and BY signals are obtained, and a good composite video signal is obtained at the terminal 21.

However, if the video signal reproduced by the head 7.8 is edited on, for example, a magnetic tape and the video signal is not continuous, the reference phase signal extracted by the reference phase signal extractor 33 will be discontinuous. Therefore, a control delay occurs by the time constant of the integrator used in the embodiment shown in FIG.

A second embodiment of the present invention which should solve this problem will be described below with reference to FIG. In FIG. 2, the same numbers as in FIGS. 1 and 4 represent the same things and perform the same operations.

39 is a phase comparator, which compares the phases of the reference color subcarrier 27 and the reference phase signal extracted by the reference phase extractor 33;
Controls the phase shifter 37.

The phase shifter 37 uses TBCll, 1 generated in the PLL 135.
TBCl 1 . 12
Since it is possible to change the signal readout timing instantaneously, the response to sudden changes at the editing point is excellent.

However, although the method of the second embodiment has advantages, T
Since the readout phase from BG11.12 is performed only in readout clock units, it is not possible to completely match the phases of the color subcarrier 27 and the color subcarrier included in the input video signal.

A third embodiment of the present invention will be described with reference to FIG. Third
The example shown in the figure is 1. This embodiment is a combination of the second embodiment.

As is clear from the above description, phase comparator 39 and phase shifter 37 are used to respond to sudden changes such as edit points, and phase comparator 34. The integrator 23 is used to completely match the phases of the color subcarrier 27 in a steady state and the color subcarrier included in the input video signal.

In addition, the phase comparison error from the phase comparator 34 and the integrator 2
It is important to stabilize the integral value from 3 in order to stabilize the entire control system. For this purpose, the phase comparator 39
The operation timing of the phase shifter 37 is made to precede the operation timing of the phase comparator 34.

Effects of the Invention According to the present invention, after separating a composite video signal into a luminance signal and two color signal components, and performing processing such as recording/reproduction or transmission,
When obtaining a composite video signal again, distortions in the high frequency range of the luminance signal and the color signal can be eliminated, and a good signal can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention;
FIG. 3 is a block diagram showing a second embodiment of the invention, FIG. 3 is a block diagram showing a third embodiment of the invention, and FIG. 4 is a block diagram showing a conventional video signal recording and reproducing apparatus. 36... Decoder, 16... Encoder, 29... Reference phase signal generator, 30...
...Adder, 11゜12...Storage means (TB
C), 36...Clock generation means (PLLI)
, 33... Reference phase signal extractor, 34...
...first phase comparison means (phase comparator), 23...
... Integrating means (integrator), 39... Second phase, comparing means (phase comparator), 37... Readout control means (phase shifter). Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure q Figure 2 Figure 3

Claims (3)

[Claims] (1) Video signal processing that separates a composite video signal into a luminance signal and two color signal components, records, reproduces or transmits it, modulates the two color signal components again, and superimposes it on the luminance signal to obtain a composite video signal an apparatus comprising: a luminance signal to be recorded or transmitted; transmission means for transmitting a first signal representative of the phase of a chrominance subcarrier in the original composite video signal together with at least one of two chrominance signal components; a storage means for storing a luminance signal, two color signals and a first signal; a clock generation means for supplying a signal readout clock to the storage means and having the phase of the clock arbitrarily variable; a first phase comparing means for detecting a phase error between the phase of the first signal and the phase of a color subcarrier modulated by the two reproduced or transmitted color signal components; and an integrating means for integrating the phase error. and controlling the clock phase of the clock generating means using the integrated value of the phase error from the integrating means. (2) Video signal processing that separates the composite video signal into a luminance signal and two color signal components, records, reproduces or transmits it, modulates the two color signal components again, and superimposes it on the luminance signal to obtain a composite video signal. a luminance signal to be recorded or transmitted; transmission means for transmitting a first signal representative of the phase of a color subcarrier in the original composite video signal together with at least one of two color signal components; storage means for storing a luminance signal, two color signals and a first signal; a clock generation means for supplying a signal read clock to the storage means; and a phase and reproduction method of the first signal read from the storage means. a second phase comparison means for detecting a phase error between the phase of the color subcarrier modulated by the two transmitted color signal components; A video signal processing device comprising readout control means for controlling a signal readout phase in units of one cycle or a plurality of cycles of the clock. (3) Video signal processing that separates the composite video signal into a luminance signal and two color signal components, records, reproduces or transmits it, modulates the two color signal components again, and superimposes it on the luminance signal to obtain a composite video signal. a luminance signal to be recorded or transmitted; transmission means for transmitting a first signal representative of the phase of a color subcarrier in the original composite video signal together with at least one of two color signal components; a storage means for storing a luminance signal, two color signals and a first signal; a clock generation means for supplying a signal readout clock to the storage means and having the phase of the clock arbitrarily variable; first and second phase comparison means for detecting a phase error between the phase of the first signal and the phase of a color subcarrier modulated by the two reproduced or transmitted color signal components; an integrating means for integrating a phase error of the comparing means; and a reading control means that is controlled by the output of the second phase comparing means and controls a signal reading phase from the storage means in units of one cycle or a plurality of cycles of the clock. The video signal is characterized in that the readout control means is operated before the first phase comparison means, and the clock phase of the clock generation means is controlled by the integrated value of the phase error from the integration means. Processing equipment.